Ads
related to: shale bedding
Search results
Results from the WOW.Com Content Network
Shale typically exhibits varying degrees of fissility. Because of the parallel orientation of clay mineral flakes in shale, it breaks into thin layers, often splintery and usually parallel to the otherwise indistinguishable bedding planes. [4]
Bio erosion caused by animals, such as bivalves, shrimp and sponges change the marine substrate, resulting in layered bedding planes, due to their sifting of bed material in search of food. Organic clastic bedding can become shale and oil shale or millions of years under pressure.
At the base of the Chittenango, [84] above the Bierne Member shale, [85] lies the Halihan Hill Bed, a highly bioturbated bioclastic limestone. [13] Further east, the homogeneous Cardiff divides into the Bridgewater, Solsville, and Pecksport shale members, from base to top. The Bridgewater is a fissile dark silty shale with relatively rare fossils.
Metamorphosed shale depicting slaty cleavage. Note the grains of mica, quartz, and ilmenite aligned with a preferred orientation. Continuous or penetrative cleavage describes fine grained rocks consisting of platy minerals evenly distributed in a preferred orientation. [1] The type of continuous cleavage that forms depends on the minerals present.
The Burgess Shale is a fossil-bearing deposit exposed in the Canadian Rockies of British Columbia, Canada. [ 2 ] [ 3 ] It is famous for the exceptional preservation of the soft parts of its fossils. At 508 million years old ( middle Cambrian ), [ 4 ] it is one of the earliest fossil beds containing soft-part imprints.
Sole markings are found on the underside of sedimentary rocks that overlie shale beds, usually sandstones. They are used for determining the flow direction of old currents because of their directional features. Sole markings form from the erosion of a bed, which creates a groove that is later filled in by sediment. [3]
Ads
related to: shale bedding